In a large pan, melt the butter over medium heat. Add the marshmallows and stir constantly until melted. Remove from heat, add the peanut butter and stir well. Add the cereal and stir until well combined. Carefully press into the pan with wax paper or buttered fingers.

Mix together the chocolate chips and 1 1/2 T. peanut butter and melt in the microwave (intervals of 30 seconds with stirring). Spread the chocolate evenly over the rice krispie's. Let sit until chocolate is set. Cut and serve.